The trucking industry is exciting. The trucks are big, the trailers are long and the freight can get reaaaal heavy.
Beyond that, there's a ton to learn and even those who’ve worked in this industry for years uncover something new every now and then. That said — to an outsider — this industry can also be overwhelming.
Getting a handle on the intricacies of the freight shipping process can be difficult and, frankly, a little frustrating. And so, you’re here hoping to learn a little bit more about how the overall weight of a freight shipment correlates to the type of trailer (and the number of axles) it’s transported on.
You know that understanding this topic and how much weight each trailer can truly carry is a great beginning step toward becoming an expert in this industry.
Here at ATS, we’ve been a staple of the U.S. trucking industry since our early days in 1955. During this time we’ve been helping customers transport all kinds of freight at all kinds of weight. Heavy haul trucking is one of our premier service offerings.
As such, we understand how the amount a shipment weighs correlates to the type of trailer it’s transported on, and — by the end of this article — you’ll understand this too.
The Relationship Between Trailer Type and Freight Weight: two things to note. . .
Before we get into the nitty-gritty of this discussion its important that you understand a couple of general rules when it comes to trailers:
1. Not All Trailers Are Created Equal
By this, I don’t mean that some trailers are of higher quality than others — although some are. Instead, I mean that the amount of weight each trailer can support varies marginally from one manufacturer to another.
Some manufacturers make their trailers a bit wider or from stronger materials so that they can handle more concentrated weight. Others manufacture trailers that have more well-space to disperse extra weight. Others still, use heavier materials like steel in their construction which limits their weight capacity slightly.
Although these discrepancies between one manufacturer and another mean little when transporting smaller quantities of freight, they can make a difference as load weight and capacity requirements increase.
With this in mind, it’s important you understand that — although the capacity thresholds listed below are great general rules-of-thumb — the exact maximum weight capacity of each trailer will vary based on the manufacturer, make and model.
2. State Regulations Will Also Impact Maximum Weight/Axle Limits
Each state has its own mandated guidelines for the maximum amount of weight that’s legally allowed to accompany each tractor/trailer set-up.
Although — in the interest of safety — the Federal Government also stipulates the legal weight limits, procedures and routes of heavy haul freight, these mandates can be adjusted state-by-state.
As such, it’s important you understand that all of the weight/trailer type capacities listed below are subject to change based on where each load is being transported.
Partnering with a seasoned transportation provider with a demonstrated history of successfully routing heavy haul freight will help you navigate these — often complex — waters.
Note, the ranges listed below are based on what each trailer CAN haul, legal weight limit restrictions — which vary by location — notwithstanding.
55,000 Pounds and Less (3-axle truck, 2-axle trailer)
The vast majority of freight occupying the roads today weighs less than the 55,000-pound capacity limitations of a five-axle setup.
As such, the two-axle: flatbed, step deck, double drop, reefer, dry van and removable gooseneck trailer (RGN) are what most shippers use for the vast majority of their shipments.
For companies that frequently transport pallet-based, boxed or consumer goods — as well as building materials and perishable freight — these five-axle rigs are more than sufficient.
55,001 - 65,000 Pounds (3-axle truck, 3-axle trailer)
As previously stated, there’s simply no “cookie-cutter” answer stating the maximum legal weight capacity of any given load.
That said, as soon as a shipment hits the 55,000-65,000 pound range, because of the weight-bearing limitations of a two-axle, adding a third axle to the normally bi-axle trailer will be necessary.
These tri-axle trailers look starkly similar to their bi-axel counterparts — apart from the added set of wheels— and come in several equipment types, including:
- 3-axle flatbeds
- 3-axle step-decks
- 3-axle removable goosenecks (RGNs)
In total, these truck/trailer combos boast six axles and do an excellent job transporting a variety of heavy haul freight.
65,001 - 84,000 Pounds (4-axle truck, 3-axle trailer)
When total freight weight falls within the range of 65,001-84,000 pounds, the time comes to incorporate the “heavy haul truck” into the freight movement process.
These quad-axle trucks possess a single axle in front (called a “steer axle”) and three axles in the back (known as the “drive axles”).
All four of these axles are necessary for supporting massive amounts of weight from point A to B.
Like the previous weight range, a three-axle trailer is used for freight weighing up to the 84,000-pound threshold.
Combine this with the quad-axle heavy haul truck and you’ll need seven total axles to transport any large machinery, generators or other heavy freight that falls within this weight range.
84,001 - 94,000 Pounds (8 total axles)
There are a couple of different ways the trailers moving freight weighing in this range can be configured. Both of these methods utilize a heavy haul quad-axle truck, but the trailer composition varies.
The first way that a carrier can secure the four trailer axles necessary for transporting freight weighing up to 94,000 pounds is by employing a “closed quad”.
Just as the name suggests, these are trailers with four axles located at the rear end of their decks. These “closed quad” trailers coupled with the four-axle truck, get you to the necessary eight total axles.
The second method for achieving four total trailer axles is to incorporate what is known as a “three plus one.” In these instances, carriers will utilize a regular tri-axle trailer accompanied by a one-axle “stinger” giving them the four total axles needed.
Note, depending on state regulations, the amount of total weight an eight-axle setup — and all subsequent configurations — can haul, changes.
94,001 - 107,000 Pounds (9 total axles)
Once a shipment’s weight arches above 94,000 pounds, there are a number of options available to get the nine total axles needed to haul that load.
This is done by incorporating combinations of pieces known as "jeep" and "booster/stinger" dollies.
Jeep Dollies (Jeeps)
Shorter trailers that include a sliding fifth wheel, kingpin and a system of suspension. These 1-3 axle units are used as the intermediary between the main trailer — hoisting the load — and the tractor.
These are 1-3-axle rear units attached immediately following the main trailer. These “stingers” — also called “tail-waggers” — are a common piece of equipment used to assist in the transport of heavy loads.
When transporting large dump trucks, dozers, excavators and rough terrain (RT) cranes that fall within the 94,001 - 107,000 pound range, here are some component combinations that make this possible:
Note, the number of axles per component, and the number of pieces used, is completely dependent on that shipment’s route and shape, state regulations and a number of other variables.
107,001 - 118,000 Pounds (10 total axles)
This is where things start to get complex. At this point, you’re transporting very large pieces of freight and doing so requires expert logistical oversight. Although the exact combination of components will vary depending on your shipment’s requirements — which is why finding an experienced provider is key — here are a few ways 10-axle combinations can be formatted:
118,001 - 125,000 Pounds (11 total axles)
Here are some jeep, trailer and stinger combinations frequently used to transport freight falling within the 118,001 - 125,000 pound range:
125,001 - 135,000 Pounds (12 total axles)
12 total axles come into play as soon as you need to move heavy loads with a minimum weight of 125,000 pounds. Like the previous few weight classes, this is done using various combinations of trailers, jeeps and stinger components.
Note, when this amount of weight is being transported, doing so becomes more of a puzzle than anything else. As such, finding a partner who understands the specifications of your shipment and how to piece together a solution to get it accomplished is important.
For your reference, here are a couple of ways for a 12-axle combination to be pieced together:
135,001 - 150,000 Pounds (13 total axles)
Any time a company needs to move freight that exceeds 135,000 pounds in weight, at least 13 axles will need to be involved. Since these shipments are so heavy, the step from 12 to 13 axles is fully necessary for distributing and supporting their heft.
Once again, there are many combinations for how a carrier can achieve the 13 axles necessary for these heavy haul shipments. A few of these combinations are outlined below:
150,001 - 225,000 Pounds (19 total axles)
Although there are some exceptions, and this is by no means a rule that’s set in stone, for the most part, shipments that exceed 150,000 pounds are transported using 19-axle trailers.
These 19-axle setups — used to haul huge tanks (vessels), boilers and generators, for example — typically look something like this:
These pieces of heavy haul equipment, featuring a 32-56 foot deck are coupled with a 4-axle truck to achieve the 19 total axle requirements of these loads.
225,001 - 360,000 Pounds (Up to 24 total axles)
The next step up when transporting heavy haul freight ranging from 225,000 (20 axles,) up to 360,000 pounds (24 axles) is to utilize what is known as a “dual-lane” trailer.
These highly specialized trailers are used to haul massive boilers, generators, tanks, oil and gas skids and more.
Just as the name suggests these dual-lane trailers transport freight along interstate highways at times when they’re legally, and safely, able to use both lanes.
Because of the disruption these shipments cause, they can take months (two to six) of planning, and — as a general rule of thumb — these trailers are only able to accomplish anywhere from six to eight hauls in a calendar year. This is tied to the slow-moving nature of these shipments which generally take upwards of a month to complete a single round trip from point A to B, and back again.
Another thing to note with dual-lane trailers is that — due to maneuverability restrictions — they often require a tractor on both ends to assist with steering. This, of course, is dependent on the length, height and weight of the freight in question.
400,000 + Pounds (Line Trailers)
Here we are at the precipice of half a million pounds. When freight hits the 400,000+ range, the only type of trailer that’s truly equipped to handle this amount of mass is the modular line trailer.
Line trailers are specialized hauling solutions that cut their teeth on their ability to add/subtract axles based on what’s necessary to adequately distribute a shipment’s weight. As such, these trailers can be adjusted to boast as many as 36 axles and are the go-to solution for freight that’s difficult to disassemble but still needs to be moved.
How to Make Your Next Shipment a Success
Now that you have a better understanding of how freight weight and trailer type operate in relation to one another, download the guide below which outlines some general rules for calculating the load weight/number of axles needed.
If you’re a shipper who needs to move a shipment that has a weight falling between 55,001 - 400,000 pounds, you’ll need to plan for the logistical aspects of these heavy haul shipments.
The best way to do so is to find a seasoned transportation partner with a demonstrated history of transporting these shipments correctly and safely. In the business of moving heavy haul shipments, nothing is more important than leveraging expertise. Finding the right partner will help you do this.
These transportation providers will help you understand how your shipment’s route in relation to its specifications will impact your timelines.
If you’d like assistance with your next freight shipment or have any questions about how ATS can help you meet your goals, deadlines and commitments, let’s talk!